3D Micro/Nano-structuring by 2PP

Two-photon
polymerization (2PP)with ultrashort laser pulses is a promising three-dimensional
microfabrication method that has recently attracted considerable attention . When
focused into the volume of a photosensitive material (or photoresist), the
pulses initiate two-photon polymerization via two-photon absorption and
subsequent polymerization. After illumination of the desired structures inside
the photoresist volume and subsequent development — e.g., washing out the
nonilluminated regions — the polymerized material remains in the prescribed 3-D
form. This allows fabrication of any computer-generated 3-D structure by direct
laser “recording” into the volume of a photosensitive material.

Because of
the threshold behavior and nonlinear nature of the process, a resolution beyond
the diffraction limit can be realized by controlling the laser pulse energy and
the number of applied pulses.

People involved

As a result, the technique provides much better
structural resolution and quality than the well-known stereolithography method.

We are
exploring applications of this technology mainly in biomedicine, in fields like microfluidics (porous
filter integration in microfluidic devices) or tissue engineering and regenerative medicine (scaffolds
for cell growth and differentiation).